• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.311-316
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• 2015

Yogurt was prepared with different substitution ratio [10, 30, and 50% (w/w)] of skim milk with enzymatically hydrolyzed purple sweet potato powder (EHPSPP) and fermented at $40^{\circ}C$ for 15 h. Fermentation characteristics and antioxidant activities of the yogurt were evaluated in terms of acid production (pH and titratable acidity) and lactic acid bacterial counts and DPPH radical scavenging activity, respectively. After 15 h fermentation, titratable acidity of EHPSPP yogurt was 0.80-0.89% and was lower than that (0.93%) of yogurt made without EHPSPP. The acid production and the number of viable lactic acid bacterial cell decreased with increasing the substitution ratio. The sensory score of EHPSPP yogurt prepared with 30% substitution ratio showed the highest values in taste and overall acceptability among the tested yogurt preparations. DPPH radical scavenging activity increased with increasing the substitution ratio in yogurt fermented for 12 h. The total phenolic content of 30% EHPSPP yogurt was 40% higher than that of skim milk yogurt. These results suggest that EHPSPP can be used as substituent of skim milk and the optimum substitution ratio is around 30%.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.60-64
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• 2005

Yogurt base was prepared from skim milk added with $0.2{\sim}1.0%\;(w/v)$ chlorella powder and fermented with lactic acid bacteria (the mixed strain of Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus thermophilus) at $40^{\circ}C$ for $12{\sim}18\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production (pH and titratable acidity), number of viable cells, viscosity and sensory properties. The addition of chlorella powder stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. After 12 h incubation, titratable acidity of chlorella yogurt was $1.16{\sim}1.33%$ and was higher than that (1.02%) of yogurt made with only skim milk. However, the viscosity of yogurt was decreased by the addition of chlorella powder. The sensory score of yogurt added with 0.2% chlorella powder was similar to ordinary yogurt in taste and overall acceptability. When chlorella yogurt was kept at $4^{\circ}C$ for 15 days, its quality-keeping properties except for number of viable cells were relatively good. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.2%.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.23-28
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• 2014

Mul-kimchi was prepared with addition of 0.025, 0.05, and 0.1% (w/v) chlorella powder and fermented at $10^{\circ}C$ for 6 days. Quality characteristics of the Mul-kimchi were evaluated in terms of acid production (pH and titratable acidity) and lactic acid bacterial counts during fermentation. The addition of chlorella powder stimulated the growth of lactic acid bacteria and significantly enhanced the acid production. After 3 days fermentation, titratable acidity of chlorella Mul-kimchi was 0.12-0.14% and was higher than that (0.11%) of Mul-kimchi made without chlorella. The acid production and the number of viable lactic acid bacterial cell increased with increasing the concentration of added chlorella powder. The sensory score of Mul-kimchi added with 0.05% chlorella powder showed the highest values in taste and overall acceptability among the tested Mul-kimchi preparations. When chlorella Mul-kimchi preparations incubated for 3 days were kept at $4^{\circ}C$ for 19 days, their quality characteristics were well maintained through storage period. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.05%.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.325-332
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• 2012

The goal of this study was to characterize the physicochemical properties, lactic acid bacteria and physiological functionality of Korean commercial Makgeolli. We collected 60 kinds of raw and pasteurized Makgeolli commercially available in Korea. Their physicochemical properties, lactic acid bacteria content and physiological functionalities were determined. In the commercial raw Makgeolli, ethanol and residual sugar content ranged from 3.6% to 9.6% and 0.20% to 4.52%, respectively. Furthermore, the raw Makgeolli contained 3.50 to 101.9 mg% of amino nitrogen. In the pasteurized Makgeolli, ethanol content ranged from 4.0% to 7.0% and their residual sugar content were 0.98% to 7.57%. The raw Makgeolli contained 2.0 $ent^3$~1.2 $ine^8$ CFU/mL of lactic acid bacteria. Among several functionalities, the antihypertensive angiotensin I-converting enzyme inhibitory activities of EDS-14 raw Makgeolli and PWR-12 pasteurized Makgeolli were very high, at 89.9% and 87.0% respectively. The other functionalities were seen to be below 30% or not detectable. The ${\beta}$-Glucan contents of the raw and pasteurized Makgeolli were noted as average, at 14.1% and 14.6%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.58-61
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• 1993

Effects of addition of 120ppm lysozyme and 0.12% glycine into Kimchi liquid on the growth of lactic acid bacteria (LAB) were investigated. The results showed that the growth of LAB was significantly reduced as much as 10$^1$~10$^4$cfu/$m\ell$ for the liquid having pH 5.5 during storage at 32$^{\circ}C$ while the liquid of pH 4.4 showed a reduction of LAB growth by 10$^1$~10$^2$cfu/$m\ell$. Combined addition of lysozyme and glycine was found to be more effective than those of individual additions. The decrease in pH of Kimrhi added with 100, 200 and 1, 000ppm lysozyme was slower than that of control, but there was no significant pH difference at late stage of fermentation. However Kimchi added with 100ppm lysozyme and 1% glycine decreased in the rate of pH change. Change in titratable acidity was also slowed up for Kimchi added lysozyme and glycine. The growth of LAB could be inhibited as much as 10$^1$to 10$^2$cfu/$m\ell$ in the Kimrhi sample added with 120ppm lysozyme and 2mM EDTA compared with other treatments including control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1533-1538
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• 2013

The objective of this study is to select an effective microbial strain to enhance the sensory qualities and functionalities of fermented ginseng soymilk. For this purpose, soybean were ground with water extracts of ginseng and fermented with five Lactobacillus strains. All strains grew well in ginseng soymilk, and viable cell counts reached greater than 8 log CFU/mL after 18 h of fermentation. The contents of total ginsenosides were higher in soymilk fermented with L. casei ATCC 393 than those in the other strains. The sensory qualities of the fermented soymilk were observed to increase with the intensity of sourness and showed the best sensory acceptability of soymilk fermented with L. kefir ATCC 35411. Moreover, the antioxidant activities, superoxide and hydroxyl radical scavenging activities were significantly enhanced by 2~4 and 4~5 times, respectively, compared to the non-fermented soymilk. In particular, the antioxidant activities of the fermented soymilk by L. kefir ATCC 35411 were the highest among the samples. This result suggests that soymilk fermented by L. kefir ATCC 35411 allowed obtaining a soymilk with enhanced sensory quality and antioxidant activity was able to contribute to the health benefit.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1247-1253
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• 1999

Yakju(rice wine) was sterilized with high-voltage pulses of short time on a batch pulsed electric field(PEF) system. The initial microbial counts of Yakju were 7.52 X $10^4\;CFU/mL$ for total aerobes, 2.20 X $10^4\;CFU/mL$ for lactic acid bacteria and 7.08 X $10^4\;CFU/mL$ for yeasts. The pH, acidity and electric conductivity of Yakju were 3.36, 0.462% and 1.24 mS/cm, respectively. Yakju was treated with 2-250 of pulses exponential-wave formed electric pulses under the field strength of 12.5-25 kV/cm. The critical strengths of the electrical field for the sterilization of Yakju were 7.5 kV/cm for total aerobes, 8.5 kV/cm for lactic acid bacteria and 6.5 kV/cm for yeasts. Logarithmic survival rates decreased linearly at low pulse number, but curvilinearly at high pulse number. The PEF sterilization kinetics of Yakju could be analysed by In s = In A-k In (n) and the sterilization rate constant increased with electric field strength and the size of target microorganisms. No changed in pH, acidity, and the growth of microorganisms were found in the PEF treated Yakju during the storage for 6 weeks at both $4^{\circ}C$ And $30^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1176-1181
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• 2012

This study was conducted to examine changes in the microbial and physicochemical properties of single-brewed Makgeolli in response to high hydrostatic pressure (HHP) treatment during various fermentation stages. HHP was applied in 2-day intervals at 400 MPa for 5 min during fermentation at $25^{\circ}C$. As a result, lactic acid bacteria showed 5~6 log reduction and reappeared at approximately 3~6 log cfu/mL as fermentation proceeded. Yeast also showed 5~6 log reduction but did not reappear during later fermentation period. HPP treatment did not result in any alcohol production on day 0 and 2. However, HPP treatment altered the pH and titratable acidity by reducing the number of microorganism. Reducing sugar contents of the samples increased continuously to 8.99% in 0 day treated sample and 5.01% in 2 day treated sample, whereas untreated Makgeolli contained 1.53% reducing sugars on 6 day due to alcohol conversion by yeast. Based on these results, HPP treatment during various fermentation stages altered the physicochemical properties of Makgeolli by changing the microbial community.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.124-129
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• 2007

We evaluated the use of citrus fruit fermented by lactic acid bacteria, as a feed supplement for flounder (Paralichthys olivaceus) cultivation. For the fermentation, a lactic acid bacterial strain W-44 showing antibacterial activity was isolated from kimchi. From the phylogenetic analysis based on, 16S rDNA sequence, the strain W-44 was identified as Lactococcus lactis. After the fermentation of citrus fruit with L. lactis W-44, the contents of naringenin and hesperetin, bioactive flavonoid aglycones, were increased about ten-fold and six-fold, respectively. The effects of fermented citrus fruit-based feed additives (CFBFA) were tested on the growth of flounder, Paralichthys olivaceus. There were significant differences in average total length and body weight between the experimental and control group. The growth rate of the experimental group fed with the 0.2% CFBFA-supplemented diet was increased 4.5% and 20.9% more than the control group in total length and body weight, respectively. These results suggest that the fermented citrus fruit could be used as a functional feed additive for flounder cultivation.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.92-97
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• 2005

This study was carried out to determine the storage, cryotolerance, heat and drying resistance, when Lactobacillus acidophilus CT 01 isolated from preweaned piglet feces growing at suboptimal temperature. L. acidophilus CT 01 suboptimal temperature incubated for 48 hours had the slowest growth rate at 22℃ but the highest viable cell number after 36 hours at 22℃, with 1.3×10/sup 9/ CFU/mL. In case of 4 and 20℃ storage, the suboptimal temperature incubated groups had a viability higher than the control (p<0.01). The cryotolerance of suboptimal temperature incubated L. acidophilus CT 01 was a higher than the control (p<0.01). When L. acidophilus CT 01 was heat treated at 60℃ for 15 minutes and 30 minutes, the suboptimal temperature incubated L. acidophilus CT 01 at 22℃ had a viability higher more than the control (p<0.01). L. acidophilus CT 01 incubated suboptimal temperature was inoculated by 30% to the carrier, and dried at 50℃ for 12 hours had the highest viability in the suboptimal temperature incubated L. acidophilus CT 01 at 28℃.